Sex Difference and Testosterone Modulation: DISCUSSION(2)

20Mar 2013

It seems unlikely that the 30-min difference in the interval between the onset of odor presentation and death can account for the absence of any AOB neuronal Fos response in the present experiments or in our previous study using breeding ferrets, although a time-course experiment is needed to definitively rule out this possibility. It is also possible that other biologically relevant odors, such as those derived from prey or from neonatal offspring, might activate the ferret’s VNO-AOB system. buy cheap antibiotics

Pheromones as well as peppermint odor augmented neuronal Fos-IR in the ferret MOB; however, only pheromonal stimuli stimulated neuronal Fos-IR in the MA and in other limbic and hypothalamic segments of the olfactory pathway. Kevetter and Winans showed that MOB mitral cells project to the anterior cortical and posterolateral cortical amygdala, which in turn provide input to the medial amygdaloid nucleus. Thus olfactory cues detected by the MOB potentially have access to the same limbic-hypothalamic regions that are activated by inputs from the VNO-AOB, although there is no evidence that the VNO-AOB system is connected to cortical olfactory areas. The present results suggest that pheromones detected by the MOE and initially processed by the MOB are able to augment neuronal activity in the MA, and depending on the sex of the subject and pheromonal stimulus presented, stimulate hypothalamic neurons as well. Several previous studies corroborate this conclusion. For example, Licht and Meredith found that individual neurons in the hamster’s MA could be activated by an electrical stimulus delivered either to receptor neurons in the MOE or in the VNO.